Separate egg yolks from egg whites. Whisk egg yolks with sugar (50 g).
When the sugar is dissolved add vanilla extract and mix well.
In a mixer bowl, whisk together very cold sour cream and heavy cream together until fluffy. Add sugar and continue whisking until firm (don't over whip).
Using a spatula, combine egg yolks with whipped cream together.
In a separate bowl, beat the egg whites with a pinch of salt until stiff.
With a spatula, carefully combine egg whites with whipped cream.
You should get a nice fluffy cream.
Spread the cream evenly into a silicone pan or salad bowl.
Cover with plastic wrap and refrigerate for 6 hours or overnight.
Rinse and drain fresh berries and puree until smooth.
If you are using a frozen berries, place them in a leak-proof container and set the container in cold water for 10-15 minutes, then puree them.
Pass the puree through a fine sieve to remove all tiny seeds. Coulis is ready.
Remove it from the silicone pan and return it back to freezer until serving. (If you used a salad bowl, place it into hot water for a couple seconds). Prepare fresh berries for garnish.
Right before serving, pour the coulis over the ice cream cake and garnish with fresh berries.